I can't comment from personal experience, but I believe the negative outcome most commonly associated with prednisone use during pregnancy is cleft palate, and you're well beyond the stage where that could happen.
I also read your other post...good luck! I hope you are able to get back into remission soon.
Status: Remission since May 2009!
Symptoms began in November 2008, ~4 weeks after giving birth to my son
Diagnosed with pancolitis on 1/30/09
Meds: Apriso (4 0.375g pills ONCE!! daily), mesalamine enema twice weekly, Natural Factors Ultimate probiotic 12/12 Formula, OrthoNovum, multivitamin. Used prednisone (starting dose 40 mg) to get into remission.